Gas mixing device



Aug. 6, 1935..

W. H. CHURCH ET AL GAS MIXING DEVICE Filed April 15, 1932 2 Sheets-Sheet l p/scm wi MAE? roe MIXED 0455s coMpzf sbe Mme/u 605 MEET,-

' INVENTORS WILLIAM H-CHUPCH B-K/DNEY. 1 HOFFMA N- W/ IA 5- TRUMPLEFP.

17mm ATTORNEY 0 Aug. 6, 1935.

w. H. CHURCH ET AL GAS MIXING DEVICE Filed April 15, 1952 2 Sheets-Sheet 2 W/LLIA CHELETON PAC/I- THEIR ATTORNEY Patented Aug. 6, 1935 UNITED STATES PATENT OFFICE GAS MIXING DEVICE Jersey Application April 15,1932, Serial No. 605,422

6 Claims. (01. 48- 186) This invention relates to mixing devices, but more particularly to a mixing device adapted to effect intermixture of gases of different calorific and pressure values.

diately upon issuance thereof from the compressing and expanding elements.

Other objects will be in part obvious and in part pointed out hereinafter.

In the accompanying drawings forming a part of this specification and in which similar reference characters refer to similar parts,

Figure 1 is a. longitudinal sectional elevation of amixing device constructed in accordance with the practice of the invention,

Figure 2 is a plan view of a mixing element interposed between the compressing and driving elements for eifecting intermixture of the gases issuing from both elements,

Figure 3 is an end view of the mixing element, v Figure 4 isa sectional elevation of a modified form of mixing element; and

Figure 5 is a sectional elevation of a modified form of mixing element having means for transferring heat from the compressed gas to the actuating gas.

Referring to the drawings and at first more particularly to Figure 1, A designates, in general, a gas mixer constructed in accordance with the practice of the invention and comprising a casing B whichmay consist of upper and lower sections C and D respectively. The casing sections C and D may be joined in the longitudinal plane of the mixer and be secured together in any suitable manner.

Within the casing B is a compressing element of the centrifugal type comprising a shaft F which extends longitudinally of the casing B and has mounted thereon an initial and a higher stage impeller G and H respectively. The impellers, of which any number may be arranged on the shaft F to assure a required final discharge pressure of the impellers G and H may be affixed to the shaft F by any convenient means (not shown).

In the end of the casing B, adjacent the inlet openings J of the initial stage impeller G, is a supply chamber K into which producer gas may be conveyed by a conduit L leading from a source of supply.

At the inner end of the supply chamber K is a wall 0 which forms a bounding surface for that end of the supply chamber and, in conjunction with a diaphragm P interposed between the impellers G and H, defines a diffusor chamber Q which encircles the impeller G to receive the fiuid issuing therefrom. The diaphragm P is pro vided with the usual passage or passages which lead from the diffuser chamber Q to the inlet openings R in the succeeding stage impeller H.

Seated against the end of the diaphragm P is a second diaphragm S, and between adjacent portions of the diaphragms P and S is a diffusor chamber T into which the fiuid compressed by the impeller H is discharged. In the, diaphragm S are discharge passages U which lead from the diffusor chamber T to a discharge chamber V in the casing B. The discharge chamber V encircles the shaft F and has an inlet opening W through which the discharge fluid passes into a conduit X whereby it may be conveyed to a desired destination. 1

The shaft F is entirely enclosed by the casing which also serves to support the shaft. In the construction shown the ends of the shaft are provided with anti-friction bearings Y arranged within supporting members Z at the opposite ends of the casing B and constituting an. end thereof. The outer ends of the supporting members Z are convenientlysealed by caps b which may be secured to the supporting members Z in any known manner. As will be readily appreciated, by disposing the shaft F entirely within the casing, the casing may be conveniently sealed at all points to prevent leakage of gases therefrom. a

Preferably, the engine whereby the shaft F and attached elements are'rotated, is also disposed within the'casing B. "The engine, selected for illustrative purposes, consists of a turbine wheel 0 of the reaction type which may be afllxed to the shaft F in a known manner and is provided with the usual radial passages d through which the actuating pressure fluid flows from the periphery of the turbine wheel. At the innermost ends of the passages d are outletopenings efrom which the expanded fluid flows into the discharge chamber V. i a

The actuating medium for. the turbine wheel c, as for instance natural gas, is supplied to the casing B by a pipe j that opens into a supply passage g in the casing B and which passage conveys the actuating gas into a supply chamber h in the casing B. Communication between the supply chamber h and the passage (1 in the turbine wheel is afforded by nozzles :i in a housing member k wherein the turbine wheel 0 is arranged.

For simplicity of illustration, such means as may be provided for controlling" the admission of actuating gas into the nozzles 7 have been omitted from the drawings, but it is to be understood that any suitable device or devices may be provided for this purpose, either for eiiecting a variation in the speed of the rotary members of the mixing device or for the purpose of varying the ultimate pressures of thegases flowing from the compressing and actuating elements.

As may be readily appreciated, gases derived from diiferent sources, as for instance producer and natural gases, are rarely of such initialtemperatures that, upon compressing the one and expanding the other into a common discharge chamber,the final temperature will be the ideal at which the device, and more particularly the actuatingielement, will operate most efficiently. Under most operating conditions the temperature of the expanded actuating gas drops to such a low value that it causes a depositionof frost particles on the elements of the device exposed thereto. Obviously, the accumulated frost has the effect of diminishing the how area of the passages thru which the actuating gas flows and will, therefore, interfere with the-performance of the device.

Apart from that related there is the further objection that the elements exposed tothe expa'nding gas will be subjected to undesirable strains of varying magnitude, depending upon the temperature'and the volume of the actuating gas. 1 In view of the foregoing considerations, it is contemplated to provide means whereby the actuating gas may bepreheated so that, upon expansion in the'wheel 0, its final temperature may approach more-nearly atmos'pheric'or room temperature'. In furtherance of'this end the compressing element, as for instance the diaphragm P, is provided with a jacket or chamber'o' which maybe saidto'iorm a portion of, or a continuationjof the supply passage 9.

' The chamber i) which preferably extends throughout the entire periphery of the diaphragm' P is defined by the wall p which constitutes a bounding surface for the passage through'which the discharge fluid flows from the impeller G to the impeller H and also along one side" of, the diffuser chamber T, into which the impeller H discharges. By connecting the pipe 1 to the casing B in such wise that the actuating gas first flows through the chamber 0 before entering the supply passage 9, proper, the heat of compression contained by the fluid or gas flow- 1 1% from the impellersjGand H will be transferredby the wall p,' tothe actuating gas. The

temperature .ofthe actuating gas will, therefore, be increased prior to its entrance into passagesv d.

. Inasmuchas the several gases are rarely of the samapotential heating value it is essential that a thorough intermingling of the discharge gas from the compressing element andthe exhaust gas from the actuatingelementbe effected in order toprevent stratification of. the two. ,For practical reasons it is, moreover, desirable that such'come mingling of the gases be brought about in close proximity to the discharge outlets of the come pressing and actuating elements since, otherwise,

a conduit'of considerable extent is required to assure-a complete-mixture of the gases which would then be efiected only by a haphazard turbulence in the gas stream.

As may be readily appreciated, to effect a correct mixture of the gases in a conduit of a length necessitated by the suggested method also renders it necessary thatthe apparatuses employed for testing the calorific value of theultimate-product be located at an impractically remote point from the mixing device. This is objectionable for several reasons. One of these is that, owing to the interval of time that elapses between the occurrence of error, that is, the introduction into the discharge chamber V of gases varying to a considerable degree from the specified calorific value, and the recording and subsequent correction of such error, a considerable volume of gas unsuitable for immediate requirements passes from the mixing device.

Another reason why it is desirable that the testing apparatus be stationed in close proximity to the mixing device is that the testing apparatus usually cooperates with such auxiliary devices as may be employed for assuring a correct mixture of the gases and which are poorly adapted for use with'apparatusrequired to be controlled from remote points.

The present invention contemplates the intimate mixture of the gases issuing fromthe compressing and actuating elements at a point immediately adjacent the discharge outlets of said elements. To this end the device A is provided with a mixing element q which is interposed between the final stage impeller of the compressing element'and the turbine wheel 0 to provide paths for the discharge fluid of the former and the exhaust fluid of the latter. a

The mixing "element q, which in Figure 1 is shown as a stationary member, may be provided with an external flange 1' adapted to lie in an annular internal groove 3 in the diaphragm S to assist in holding the mixing element q against longitudinal movement and also to retain it in substantially coaxial relationship with the shaft F, which it encircles; p

The peripheral zone of theportion of the mixing element q which'lies adjacent the wheel 0 may extend into the mixing chamber'V. This portion of the mixing element is preferably in the form of an endless wall't arranged in zig-zag fashion about the axis of the mixing element. More specifically, the wall I re" resents a series of V-shaped members it of which the free ends of the legs abut. The sides of the V-shaped niembers u are, therefore, angularly disposed with respect to the longitudinal axes of the mixing element q and the shaft F. Y The wall t serves to provide two sets of passages arranged in alternate fashion and of which those passages designated c registerwith the discharge passages U of' the compressing element. The other set of passages, designated 10, serve to convey discharge fluid from the passages d of the turbine wheel into the discharge chamber V.

In order that thegases issuing from the discharge passages U and the outlet openings 2 may be gradually directed into the discharge chamber V from the longitudinally directed outlet openings of the passages U and e the bottom surfaces a. of the members it are inclined with respect to the longitudinal axis of the mixing element. In consequence of this arrangement the gases issuing from the compressing and actuating elements may be gradually'deflected along a gradually deviating path into-the discharge chamber.

' "In practice it hasbeen found that, as a general rule, in gas mixing devices of the various known types, it happens only infrequently that the mix- .tureobtained by intermingling gases of different heating values meets the specified potential heat content. More often it requires enriching and means are accordingly, provided herein'to intro.- duce gas'of a high heating value intothe mixer tocombine, in this instance, with the gas flowing from the compressing element intoithe discharge chamber.

The diaphragm S is accordingly provided with a chamber y which communicates with the discharge passage or passages U. through a series of nozzles 2, also located in the diaphragm S. The make-up gas may, as indicated, be natural gas which is conveyed into the chamber y by a pipe 2 connected at one end to the casing Band with its opposite end to the pipe 1, as for instance, at a point between the source of natural gas supply and a valve 3 disposed in the pipe f for controlling the flow of gas into the chamber 0. The pipe 2 may likewise be provided witha valve 4 for controlling communication between supply and the chamber y. a I

The operation of the device is as follows: Let it be assumed that the inlet chamber K and the supply chamber h are both in free communication with theirrespective sources of gas supply. The gas in the supply chamber it being under pressure will actuate the turbine wheel and associated elements, including the impellers G and H. The gas drawn into the inlet openings J of the impeller G passes therethrough, thence through the associated passages into the impeller H whereby it is compressed to a higher value and discharged into the diifusor chamber T.

From the diffusor T the fluid discharged from the impeller H flows through the discharge passages U, thence through the guide passages 12 which are in direct communication with the discharge passage U. Similarly, the expanded fluid issuing from the outlet openings e of the passages d flows through the guide passages to into the discharge chamber V.

The discharge gas from the impellers G and H and the exhaust gas from the turbine wheel 0 will thus pass from these elements as alternate jets or streams which are directed laterally with respect to each other so that the gases will be thoroughly mixed in the discharge chamber V before the resulting mixture passes therefrom into the conduit X.

During its passage through the chamber 0 the actuating gas will absorb or abstract heat from the wall p of the diaphragm S and the temperature of the actuating gas will be materially increased so that, upon expanding in the turbine wheel 0, the temperature of the actuating gas entering the discharge chamber V will be of sufficiently high value to obviate any adverse effect upon the device.

In the event that the resulting product of the gases issuing from the compressing and actuating elements should be deficient in calorific power additional gas may be supplied to the discharge output of the compressing element by opening the valve 4. The augmenting gas then flows into the discharge stream of the compressing element and passes therewith into the guide passages in the mixing element where it will be thoroughly mixed with the exhaust gases from the turbine wheel.

In practice it has been found that the present invention is highly efficient as a means for mixing gases derived from different sources, as for instance manufactured and natural gases. Owing to' the difference in the pressure values of the gases, the energy of the one may be employed for compressing the other. The two gases may be intimately mixed at a point closly adjacent the compressing and actuating elements of the mixer. Moreover, all the movable or rotary elements of the device may be conveniently disposed within a single casing which may, because of that fact, be adequately sealed, thereby eliminating all chances of leakage of gas from the mixing device.

The modified form of the invention shown in Figure 4 differs from that previously described principally in that the mixing device is provided with a mixing element or drum designated 5 which is afiixed to the shaft F by means of a key 6, or otherwise, so that the mixing element 5 rotates with the shaft. In addition toits function .of conveying exhaust and discharge gases from the actuating and compressing elements the mixing device 5 also, due to its rotative movement, serves asa means for whirling and thoroughly mixing the gases which it conducts .into the discharge chamber V.

In themodification illustrated in Figure 5 the mixing device designated by 1 may, insofar as its mixing function is concerned, be substantially like the mixing device q, particularly with respect to the guideways, the walls whereby the guideways are formed and the manner in which the discharge and exhaust outlets of the compressing and actuating elements communicate with the guideways. ticularly to an arrangement for transmitting the heat of compression, from the discharge gas issuing from the compressing element, to the actuating gas employed for actuating the rotary parts of the device.

The mixing element 1 is accordingly provided with deflecting means, as for instance baflles 8 arranged in the guideways v. The baflles 8 are suitably spaced from the surface x of the guideways v to form therebetween passages 9 through which a portion of the discharge fluid issuing from the dis charge passages U may flow into a chamber I 0 in a housing member ll wherein the turbine wheel 0 is arranged.

In a wall l2, which separates the chamber l0 from the discharge chamber V, are ports l3 that afford communication between the passages 9 and the chamber in. The chamber I0 is separated from the nozzles a through which the actuating gas flows into the turbine wheel only by a wall I 4 which serves to transfer the heat of the discharge fluid directed into the chamber I U to the gas flowing through the nozzles 7. The wall I2 is further provided with a series of exhaust ports l5 to conduct the gas from the chamber H] to the discharge chamber.

As will be readily apparent, owing to the arrangement described, there will be a constant flow of heated gas from the compressing element through the heating chamber II]. By arranging the exhaust ports l5 closely adjacent the region where the gases issue from the guideways v, w, the gas flowing from the heating chamber ID will be thoroughly mixed with those issuing from the mixing element.

We claim:

1. A gas mixing device comprising a centrifugal compressor, a shaft therefor, a pressure actuated engine on the shaft for driving the compressor, and a drum keyed to the shaft and having two sets of passages leading from opposite ends of the drum and being arranged in alternate This modification relates more par- 'fashion for conveying the discharge fluid from the compressor and the exhaust fluid from the engine and forefiecting intermixture of both fluids.

2. A gas mixing device comprising a centrifugal compressor, a shaft therefor, a pressure actuated engine on the shaft for driving the compressor, a common. discharge chamber for the compressor and the engine, and a mixing element rotatable with the shaft and having passages to convey relatively laterally directed jets of discharge fluid from the compressor and exhaust fluid from the engine for effecting intermixture of the fluids.

3. A gas mixing device comprising a casing having a discharge chamber, a compressor for gas and having a discharge passage opening into the discharge chamber, an engine actuated by gas under pressure and exhausting into the discharge chamber, means for introducing gas of a comparatively high calorific value into the discb arge passage, and a mixing element for effecting intermixture of the gases flowing'from the discharge passage and the engine to the discharge chamber.

4. A gas mixing device compris ng a casing having a discharge chamber, a compressor for gas having a wall to define a discharge passage opening into the discharge chamber, an engine actuated by gas under pressure and exhausting into the discharge chamber, and a supply passage for the engine having a portion thereof bounded by the wall, whereby the heat of compression is transferred by the wall from the compressed fluid to the pressure gas flowing through the supply passage.

" 5. A gas mixing device comprising a casing having a discharge chamber, a compressor for gas having a wall to define a. discharge passage opening into. the discharge chamber, an engine actuated by gas under pressure and exhausting into. the discharge. chamber, a mixing element for effecting intermixture of the gases flowing from the discharge passage and the engine to the discharge chamber, and a supply passage for the engine having a portion thereof bounded by the wall, whereby the heat of compression is transferred by the wall from the compressed fluid to the pressure gas flowing through the supply passage.

6. A gas mixing device comprising a casing, a compressor for gas, an engine actuated by gas under pressure and being connected to drive the compressor, a wall in the casing for transferring theheat of compression from the compressor dis charge fluid to the gas under pressure flowing to the engine, and a mixing element for efiecting intermixture of the gases flowing from the discharge passage and the engine to the discharge chamber.

WILLIAM H. CHURCH. CARLETON B. KIDNEY. PAUL HOFFMAN. WILLIAM E, TRUMPLER. 

